By the early 1950s Toronto had truly become a car city. Every day people would commute downtown, creating huge amounts of traffic on their way. At the time it was difficult to expand transportation networks between Toronto and the surrounding municipalities because they had separate governments so in 1953 the Provincial Government created a new Metropolitan Toronto council to manage, amongst other things, Metro-wide transportation.

The first chair of the Metropolitan Toronto council was Forest Hill resident Frederick Gardiner. Gardiner quickly drew up plans for a system of expressway and parkway arterials that expanded outward from the city centre. Gardiner's plan included five total arterials including the Gardiner Expressway, the Don Valley Parkway and the Spadina Expressway, which would spread to the outer reach of the metropolitan region and encourage suburban growth.

In the end only the Gardiner and the Don Valley Parkway were completed, and only the DVP was finished with minimal opposition. Since it was built in the riverbed its building did not require the demolition of existing homes (unlike the proposed Spadina Expressway, which encountered massive resistance) and it was easily integrated with existing street systems. Also, by calling the DVP a "Parkway", the Metro council signalled their intention to integrate the road with the river valley. Unlike the Gardiner, which cut in a straight line through existing neighbourhoods, the DVP appeared to blend in with its surroundings. The DVP did, however, have a massive effect on the surrounding ecosystem and forever changed the relationship between the city and the river.

The Gardiner Expressway and the Don Valley Parkway were completed by 1964 and 1966 respectively and are the now the only East-West and North-South arterials that enter the downtown core of Toronto.

Jennifer Bonnell, Reclaiming the Don: An Environmental History of Toronto's Don River Valley (Toronto: U of T Press, 2014).